Quantum GIS API Documentation  1.7.4
src/core/qgsvectordataprovider.h
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00001 /***************************************************************************
00002     qgsvectordataprovider.h - DataProvider Interface for vector layers
00003      --------------------------------------
00004     Date                 : 23-Sep-2004
00005     Copyright            : (C) 2004 by Marco Hugentobler
00006     email                : marco.hugentobler@autoform.ch
00007  ***************************************************************************
00008  *                                                                         *
00009  *   This program is free software; you can redistribute it and/or modify  *
00010  *   it under the terms of the GNU General Public License as published by  *
00011  *   the Free Software Foundation; either version 2 of the License, or     *
00012  *   (at your option) any later version.                                   *
00013  *                                                                         *
00014  ***************************************************************************/
00015 /* $Id$ */
00016 #ifndef QGSVECTORDATAPROVIDER_H
00017 #define QGSVECTORDATAPROVIDER_H
00018 
00019 class QTextCodec;
00020 
00021 #include <QList>
00022 #include <QSet>
00023 #include <QMap>
00024 
00025 //QGIS Includes
00026 #include "qgis.h"
00027 #include "qgsdataprovider.h"
00028 #include "qgsfeature.h"
00029 #include "qgsfield.h"
00030 #include "qgsrectangle.h"
00031 
00032 typedef QList<int> QgsAttributeList;
00033 typedef QSet<int> QgsFeatureIds;
00034 typedef QSet<int> QgsAttributeIds;
00035 
00044 class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider
00045 {
00046     Q_OBJECT
00047 
00048   public:
00049 
00050     // If you add to this, please also add to capabilitiesString()
00054     enum Capability
00055     {
00057       NoCapabilities =                     0,
00059       AddFeatures =                        1,
00061       DeleteFeatures =               1 <<  1,
00063       ChangeAttributeValues =        1 <<  2,
00065       AddAttributes =                1 <<  3,
00067       DeleteAttributes =             1 <<  4,
00069       SaveAsShapefile =              1 <<  5,
00071       CreateSpatialIndex =           1 <<  6,
00073       SelectAtId =                   1 <<  7,
00075       ChangeGeometries =             1 <<  8,
00077       SelectGeometryAtId =           1 <<  9,
00079       RandomSelectGeometryAtId =     1 << 10,
00081       SequentialSelectGeometryAtId = 1 << 11,
00082       CreateAttributeIndex = 1 << 12,
00084       SetEncoding = 1 << 13,
00085     };
00086 
00088     const static int EditingCapabilities = AddFeatures | DeleteFeatures |
00089                                            ChangeAttributeValues | ChangeGeometries | AddAttributes | DeleteAttributes;
00090 
00095     QgsVectorDataProvider( QString uri = QString() );
00096 
00100     virtual ~QgsVectorDataProvider();
00101 
00105     virtual QString storageType() const;
00106 
00114     virtual void select( QgsAttributeList fetchAttributes = QgsAttributeList(),
00115                          QgsRectangle rect = QgsRectangle(),
00116                          bool fetchGeometry = true,
00117                          bool useIntersect = false ) = 0;
00118 
00123     virtual long updateFeatureCount();
00124 
00136     virtual bool featureAtId( int featureId,
00137                               QgsFeature& feature,
00138                               bool fetchGeometry = true,
00139                               QgsAttributeList fetchAttributes = QgsAttributeList() );
00140 
00146     virtual bool nextFeature( QgsFeature& feature ) = 0;
00147 
00152     virtual QGis::WkbType geometryType() const = 0;
00153 
00154 
00159     virtual long featureCount() const = 0;
00160 
00161 
00165     virtual uint fieldCount() const = 0;
00166 
00172     virtual const QgsFieldMap &fields() const = 0;
00173 
00178     virtual QString dataComment() const;
00179 
00181     virtual void rewind() = 0;
00182 
00191     virtual QVariant minimumValue( int index );
00192 
00201     virtual QVariant maximumValue( int index );
00202 
00211     virtual void uniqueValues( int index, QList<QVariant> &uniqueValues, int limit = -1 );
00212 
00218     virtual void enumValues( int index, QStringList& enumList ) { Q_UNUSED( index ); enumList.clear(); }
00219 
00224     virtual bool addFeatures( QgsFeatureList &flist );
00225 
00231     virtual bool deleteFeatures( const QgsFeatureIds &id );
00232 
00239     virtual bool addAttributes( const QList<QgsField> &attributes );
00240 
00247     Q_DECL_DEPRECATED virtual bool addAttributes( const QMap<QString, QString> &attributes );
00248 
00254     virtual bool deleteAttributes( const QgsAttributeIds &attributes );
00255 
00261     virtual bool changeAttributeValues( const QgsChangedAttributesMap &attr_map );
00262 
00266     virtual QVariant defaultValue( int fieldId );
00267 
00275     virtual bool changeGeometryValues( QgsGeometryMap & geometry_map );
00276 
00281     virtual bool createSpatialIndex();
00282 
00284     virtual bool createAttributeIndex( int field );
00285 
00291     virtual int capabilities() const;
00292 
00296     QString capabilitiesString() const;
00297 
00301     virtual void setEncoding( const QString& e );
00302 
00306     QString encoding() const;
00307 
00311     int fieldNameIndex( const QString& fieldName ) const;
00312 
00314     QMap<QString, int> fieldNameMap() const;
00315 
00319     virtual QgsAttributeList attributeIndexes();
00320 
00325     void enableGeometrylessFeatures( bool fetch );
00326 
00331     bool supportedType( const QgsField &field ) const;
00332 
00333     struct NativeType
00334     {
00335       NativeType( QString typeDesc, QString typeName, QVariant::Type type, int minLen = 0, int maxLen = 0, int minPrec = 0, int maxPrec = 0 ) :
00336           mTypeDesc( typeDesc ), mTypeName( typeName ), mType( type ), mMinLen( minLen ), mMaxLen( maxLen ), mMinPrec( minPrec ), mMaxPrec( maxPrec ) {};
00337 
00338       QString mTypeDesc;
00339       QString mTypeName;
00340       QVariant::Type mType;
00341       int mMinLen, mMaxLen;
00342       int mMinPrec, mMaxPrec;
00343     };
00344 
00345 
00350     const QList< NativeType > &nativeTypes() const;
00351 
00352 
00357     Q_DECL_DEPRECATED const QMap<QString, QVariant::Type> &supportedNativeTypes() const;
00358 
00362     virtual bool doesStrictFeatureTypeCheck() const { return true;}
00363 
00364 
00365     static const QStringList &availableEncodings();
00366 
00367     /* provider has errors to report
00368      * @note added in 1.7
00369      */
00370     bool hasErrors();
00371 
00372     /* clear recorded errors
00373      * @note added in 1.7
00374      */
00375     void clearErrors();
00376 
00377     /* get recorded errors
00378      * @note added in 1.7
00379      */
00380     QStringList errors();
00381 
00382 
00383   protected:
00384     QVariant convertValue( QVariant::Type type, QString value );
00385 
00386     void clearMinMaxCache();
00387     void fillMinMaxCache();
00388 
00389     bool mCacheMinMaxDirty;
00390     QMap<int, QVariant> mCacheMinValues, mCacheMaxValues;
00391 
00393     QTextCodec* mEncoding;
00394 
00396     bool mFetchFeaturesWithoutGeom;
00397 
00399     bool mFetchGeom;
00400 
00402     QgsAttributeList mAttributesToFetch;
00403 
00405     QList< NativeType > mNativeTypes;
00406 
00407     void pushError( QString msg );
00408 
00409   private:
00411     QMap<QString, QVariant::Type> mOldTypeList;
00412 
00413     // list of errors
00414     QStringList mErrors;
00415 
00416 
00417     static QStringList smEncodings;
00418 
00419 };
00420 
00421 #endif
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